The present invention relates to the triggering and firing mechanism of a firearm. Conventional firearm mechanisms are totally mechanical, relying on a set of levers, springs, and sears to transform the pull of the trigger lever to a release of the firing pin. Despite their development over a period of literally hundreds of years, these mechanisms continue to have limitations. The sensitivity of the mechanism cannot be increased beyond a point without increasing limitations on reliability and without increasing cost. Furthermore, the mechanism cannot be readily adjusted by the operator to account for different preferences in areas such as trigger pull or the number of shots fired per trigger pull (in the case of an automatic firearm). The mechanical structure also places certain limitations on the nature of the safety and locking mechanism.
A number of triggering mechanisms have been proposed that use electro-mechanical devices to release the firing mechanism of a firearm (e.g. U.S. Pat. No. 4,757,629; U.S. Pat. No. 4,347,679; U.S. Pat. No. 4,329,803; U.S. Pat. No. 4,275,521). The mechanical release of the firing pin is replaced with a release mechanism that is electrically induced. These devices focus primarily on target shooting, where they seek advantages of cost-effectiveness and a simpler releasing mechanism than more expensive mechanical target firearm triggers.
The prior work on electro-mechanical triggering devices centers primarily on the release mechanism for the firing pin. In all cases, the trigger lever operated by the shooter is a mechanical switch similar in nature to conventional fully mechanical triggers or, in some cases, similar in function to a mechanical electric switch.
With the exception of the firearm proposed in U.S. Pat. No. 4,275,521, these electrical mechanisms employ an electromagnet with a moveable armature. These devices by nature involve a comparatively long release time because it takes time for the magnetic field to build up once the electric circuit is turned on. Also, the use of electromagnetic force requires an ample battery storage, which is difficult to provide in the limited space of a firearm. While such a battery may be practical in target shooting, it would be cumbersome and unreliable for many other firearm applications. Furthermore, the array of electrical components, typically including magnets, capacitors, and solenoid coils, tends to be heavy, bulky, and of questionable reliability for some firearm applications.
U.S. Pat. No. 4,275,521 proposes a firearm in which an electromagnet for releasing the firing pin is replaced by a piezo-electric element. This requires less electric current than the aforementioned magnetic devices, and also has a shorter release time. The present invention improves on this application is several ways. First, it contemplates the use of recent piezo-electric products, such as polyvinylidene fluoride (PVDF), which are not mentioned as possible piezo-electric agents in the above patent. Second, it extends the use of the piezo-electric technology beyond the firing mechanism to the trigger lever operated by the shooter, and to the safety mechanism for the firearm. Third, it seeks to exploit the flexibility and control inherent in electronic devices to allow the operator to control the specifics of the firing mechanism in the field.